Letter: Vitamin debate

Whether or not giving higher dosed vitamin D supplements can improve or prevent certain conditions and diseases will have to be shown in randomised trials as Professor Sattar suggested (your report, 13 January).

However, by definition, 70-80 per cent of the whole Scottish population is deficient and it makes sense to have Vitamin D supplements prescribed by GPs, like myself, just like they prescribe folic acid to all pregnant women and vitamin B12 to those who are deficient.

Even if it only keeps bones healthy, it is worthwhile to avoid deficiency.

It used to be thought that just a small amount of daylight would be sufficient to make enough vitamin D in the skin. Now it is understood that our bodies and bones function better with higher blood levels of vitamin D (measured as 25(OH)D).

But we all work and live indoor and don’t get enough sun on the skin – 400 IU (10 mcg) daily are not sufficient to raise 25(OH)D levels above 50 nmol/l in adults and pregnant women. Research has shown 4,000 IU (100 mcg) daily are safe (Institute of Medicine, US).

Because there is such a high rate of deficiency and it is perfectly safe to take a decent sized supplement, supplementation should really be recommended to all people living in Scotland and testing would not need to be done before.

For some people with severe diseases, however, it might be useful to check whether the desired level is reached several months after the start of supplementation.

Helga Rhein

Sighthill Health Centre

Calder Road

Edinburgh